(1) Field of the Invention
The present invention relates to an electromagnetic welding method for welding a metal plate to a core wire of an electric wire and to a conductor module in which a metal plate is welded to a core wire of an electric wire.
(2) Description of the Related Art
For example, a wiring harness mounted on a motor vehicle includes electric wires and terminal fittings as metal plates attached to ends of the electric wires. The electric wire includes a core wire and an electrically insulating coating for coating the core wire. The core wire consists of a plurality of element wires made of metal such as copper. The terminal fitting is formed by bending a flat sheet metal made of electrically conductive metal.
So far, when the terminal fitting is electrically and mechanically connected to the electric wire, a part of the terminal fitting is caulked to the electric wire. Therefore, for example, if the wiring harness is mounted on a motor vehicle, vibrations during travelling of the motor vehicle causes the electrical connection between the terminal fittings and the electric wires to be unstable.
When a metal plate such as the terminal fitting is welded to a core wire of the electric wire, for example, an electromagnetic welding method (for example, see Japanese Patent Application Laid-Open No. H11-192562) may be used.
If a metal plate is welded to a core wire of an electric wire by using the electromagnetic welding method disclosed in Japanese Patent Application Laid-Open No. H11-192562, since the core wire is exposed at end parts of the electric wire and since there is a bias in a distribution of electromagnetic force (i.e. force in a direction in which the metal plate adheres to the core wire) on a surface of the metal plate, therefore the element wires of the core wire might disperse undesirably. If the element wires disperse, each of the element wires moves during welding, resulting in that the core wire might fail to be welded to the metal plate or that the welding area thereof might be very small and therefore, this welding method might not be appropriate for connection between the terminal fitting and the electric wire.